a. Field of the Invention
The present invention relates generally to apparatus for a portable cutting and boring holes in countertops formed of stone and similar materials, and, more particularly, a guide assembly for directing a cylindrical, rotary bit when cutting a hole in a countertop that is formed of such a material.
b. Related Art
Stone countertops are an increasingly popular feature of both residential and commercial construction, valued for both their durability and beauty. As used in this description and the appended claims, the term “stone” includes natural stone (e.g., granite, marble, and so on) and artificial stone materials. The term “countertop”, in turn, includes not only kitchen and bathroom counters, but also worktops, tub surrounds and similar installations.
A major difficulty facing installers is cutting/boring holes to accommodate various items that must pass through the countertop, such as faucets and other plumbing fixtures, wiring, and so on. This must be done after the countertop itself has been placed into position and installed. As a result, the holes must frequently be formed in corners, along edges, and in other areas where access is limited or difficult. The operation is further complicated by the fact that the surface must be kept flooded with water or other lubricant for the bit during the cutting operation. However, even a minor error in the location or angle of the hole can ruin the countertop so that it must be removed and replaced, at great expense to the installer; such errors are far from infrequent, and cost even experienced installers many thousands of dollars every year.
Prior devices have been proposed to provide guidance for a bit or other cutting tool when forming holes in stone or similar materials. The great majority of these devices are simply too large and cumbersome for use in countertop installation work, especially where the holes need to be formed in tight areas or close to an obstacle; many have been designed as shop tools that would be wholly unsuitable to the needs of a craftsman drilling a hole at the point of installation. In other instances, the devices, although smaller, have been insufficiently secure to avoid slippage and error. Most prior devices have also been complicated and expensive, and moreover have been difficult and inconvenient to use. Also, many of the prior devices employ or require the use of obsolete forms of drill motors that are no longer used in the industry; for example, pistol-grip drills are no longer used for coring bits, which now utilize industry-standardized acme threads. As yet another drawback the prior devices have generally been constructed with metal bodies or housings, thus making it virtually inevitable that the countertop or adjoining surfaces will be scratched or otherwise marred during use of the tool.
Accordingly, there exists a need for an apparatus for guiding a rotating bit while forming a hole in a stone countertop, that securely attaches to the countertop so as to obviate any potential for slippage and error. Furthermore, there exists a need for such an apparatus that can be conveniently used in areas where access or space is limited. Still further, there exists a need for such an apparatus that provides a reservoir in order to keep the material and bit flooded with fluid during the cutting operation. Still further, there exists a need for such an apparatus that can be used with conventional hole-cutting bits and tools that does not require the installer to purchase special drill motors/equipment. Still further, there exists a need for such an apparatus that is simple and convenient for the operator to use. Still further, there exists a need for such an apparatus that can readily accommodate the different sizes of bits that are used in forming holes in countertops. Still further, there exists a need for such an apparatus that obviates the possibility of scratching, marring or otherwise damaging the countertop and adjoining surfaces. Still further, there exists a need for such an apparatus that can be manufactured on an economical basis.